Examples and Applications

Our portfolio of customers in the marine sector include shipyards and naval engineering consultants dealing with hydrodynamic optimisation of ship hull forms and propulsion systems, as well as construction and civil engineering companies responsible for the design of costal and offshore structures. The main CFD tools employed for this type of applications are HELYX and HELYX-Marine. The HELYX-Marine add-on module has been developed by ENGYS in conjunction with Prof. Kevin Maki of the Department of Naval Architecture and Marine Engineering of the University of Michigan to deal with hydrodynamic ship hull design.

Calm Water Resistance

CFD models are important for ship designers because hydrodynamic performance can be verified using full size hull models, thus eliminating the scaling issues experienced in the towing tank with the Reynolds and Froude numbers.

The specialised fast solver in HELYX-Marine is employed to predict ship hull resistance in calm waters, including basic sinkage and trim approximations. Since this method is about 100 times faster than the equivalent VOF multi-phase solver approach, it is often used in combination with a design optimisation tool (such as DAKOTA or CAESES) to minimise resistance and improve the overall hydrodynamic performance of the hull. The fast solver and optimisation procedure are described in detail in a joint paper by ENGYS, Fincatieri and University of Michigan presented at COMPIT 2012: Hull Design Method Combining an Innovative Flow Solver Coupled With Efficient Multivariate Analysis and Optimization Strategies.

Seakeeping Analysis

The HELYX-Marine add-on module also features a set of transient solvers and dedicated utilities to simulate floating bodies and seakeeping conditions in forward motion, including waves analysis and self-propulsion models. The 5DoF solver with enforced surge motion is used to simulate various seakeeping conditions, dynamic sinkage and trim and added resistance in waves. The 6DoF solver, on the other hand, is reserved to simulate floating offshore structures, buoys, etc.

The ability of the solvers to deliver accurate results for seakeeping conditions has been proven following a extensive validation program against experimental data available from both our customers and the literature. Some of the ship models employed to test our solvers include the MOERI KCS, JHSS (US Navy) and the US-Navy CG-47 Cruiser, among others.

CFD simulation of offshore tug in cross waves with HELYX.


Contact your nearest ENGYS office today to discuss your specific applications with one of our engineers and learn more about how we can help you realise your designs using our open-source CFD software products and services.